Biomass refers to the photosynthesis of various biological material from carbon dioxide and water. It can store solar energy in chemical form, renewably store biosphere carbon, and is an important link of the carbon cycle on earth. Biomass mainly in the form of tree such as twig, agriculture waste such as wheat and rice straw, corn stover, as well as grass such as switch grass. These biomass mainly composed with cellulose, hemicelluloses and lignin entangling to form dense texture, resisting to separation and degradation. Thus the de-polymerization and processing is one of the biggest bottle neck of biomass material utilization. The breakthrough of this barrier would improve the economy of biofuel ethanol, increase the supply of bio-originated bulk chemicals, and increase the competition of environment friendly polylactic acid over mineral oil based plastic.
Reference search showed that a Chinese patent (Chinese patent no. 02145150.8) revealed a process of hydrolysis of biomass with diluted acid under temperature of 100-200° C. for preparation of reduced fermentable mono-sugar. Since the dilute acid used is mineral acid as in other strong acid process, there exist the same disadvantage of different recovery and low recycle of mineral acid, waste discharge polluting environment.